Tx Power Adjustment – Why Change Router Tx Power, And Is It Safe?

Tx Power Adjustment - Why Change Router Tx Power

What is Tx Power?

In basic terms it is how many milliwatts of power is transmitted outbound from the router to the antenna. The antenna then puts ‘gain’ on the signal (we won’t cover that here, otherwise this article will be as long as War and Peace!!!).

Router Tx Power Adjustment – Why?

Most consumer routers don’t give the option as standard, but some Asus routers do (the RT-AC66U for example has a Tx Power Adjustment option), and of course, if you have flashed your router (DD-WRT, Tomato etc), the option to adjust power levels are there.

Adjusting the power, and that means increasing AND decreasing, can in some cases help with coverage and data rates, especially at distances further away from the router.

Be Careful Changing The Router Power!

The client will most likely have a weaker receive and transmit signal than the router. So, if you crank up the router’s TX power, the router will be yelling to the client, the client will hear it, but the client won’t be able to reply with the same ‘noise’ as the router, because it doesn’t have as much transmit power..

Ok, ‘noise’ is maybe not the best term to use here, as ‘noise’ can also be known as interference, and that is definitely not what we mean.

Basically, if the TX signal on the client is not as strong as the router, then as the client moves away from the router, the client will be less likely to ‘shout’ loud enough for the router to hear it talking back.

This isn’t always the case all of the time, there are so many variables, so experimentation is the key.

Rule of thumb is to try to keep the transmit power as low as possible, but enough so that the clients can talk to the router. Boosting the Tx power too much can actually hinder performance, because of the increased noise levels, as previously mentioned.

100mw is usually about the maximum amount of power you want to set your router to. This is not in all cases, but it works for most users.

Also, be ethical. You need to check what the allowed outputs are for your country/region. There are actually laws in place that limit the amount of power an Access Point or router can transmit. The reason for this is to stop wildly congested airspace in built up areas.

Can you imagine an apartment block in a city where everyone just cranked up the power? There would be congestion on all bands and everyone would suffer. So think carefully before making any adjustments.

Don’t want to adjust anymore? Want to try something else? Check out the 10 ways to boost your wifi signal

Is Adjusting The Power Safe? Are There Downsides?

Tx Power Adjustment - Why Change Router Tx Power

Increasing transmit power on the router can produce bad side-effects:

It can increase the noise – When we say noise, we mean signal noise. Not actual noise that you hear! (in case you were wondering). Noise is most often background ambient noise and/or interference, and when the power is increased, so is the noise.

Increased noise drowns out the actual quality wifi signal that the data loves to be transported on. When this happens it makes it more difficult for sending and receiving stations to communicate. This slows down data transfers, increases packet loss and affects coverage. Bad news, especially for the gamers!

It can make your router very hot! – This in turn can bring the lifetime of your router down significantly. It’s not a hard, fast rule, but it certainly doesn’t help the potential longevity of your networking device. In fact, it is best practice to turn off wifi on your router when you are not using it, regardless of how much power is being used – if you want the components to last longer, that is.

There’s also the effects of wireless signal on the human body to consider. Ok, so there are no hard facts, but although the amount of wifi power/signal is relatively weak, no-one really knows how much of an impact wireless signals have on our health.

How To Test The Signal When Adjusting The Tx Power

To test the signal (the cheap and cheerful way), install a Wi-Fi analyzer on your laptop. A Wi-Fi analyzer shows wireless output per channel in a graph mode on the band of your choosing. It makes it pretty easy to read how much signal you are receiving from your router. And perhaps more importantly, it tells you what other routers/APs are broadcasting in your area, that your laptop is picking up.

Oftentimes, it’s just a matter of changing the settings on your router to another channel that is less congested. This more often than not improves performance and coverage more than increasing the Tx power on the router.

If there are no other routers (from your neighbors) interfering with the channel your router is using, then try incrementing or decrementing the Tx power in gradual increments. Then with a wireless analyzer – like Acrylic Wifi software for example (it’s free), you can see how much the signal is affected at given physical distances away from your router.

We love Metageeks’ Inssider too, but sadly that is no longer free.

Acrylic Wifi

acrylic-wifi - Why Change Router Tx PowerCourtesy Acrylic Wi-Fi


Make sure you jot the RSSI figures down from the same designated spots in your home, and compare them after making power tweaks.

The closer the RSSI figure is to zero, the stronger the signal is. You could also take screenshots if that’s easier for you.

You can even use your laptop’s operating system for info.

Within Windows (Win 10 in this example), go to:
Network and Sharing Center > click you wifi network

Network and Sharing Center

Win 10 Network and Sharing center


> then look at the speed.

Win 10 Wi-Fi Status

Win 10 Wi-fi box

Alternatives To Tweaking The Tx Power Level – Ways To Get A Better Wi-Fi Signal

Use better antennas
High gain antennas or antennas which have low impedance can work well. At least, they can work better than router stock antennas. Be careful with high gain antennas however. The beamwidth can be narrower, so angling the antennas can become even more important.

Angle the antennas
If you have a multi-story home, you definitely want to adjust the angle of your antennas. On a 3 antenna minimum router, adjusting two of the antennas to 45 degrees (from vertical) can help. Leave the third antenna vertical.

By doing this, the beamwidth is angled to cut across the other storys in your home.

If you have a 3 story home, try to position the router in the middle floor.

Use a second Access Point (AP)
An Access Point can be a dedicated AP, or a wireless router. Whatever you choose, make sure it is on a non-overlapping channel and placed far away from the original wifi router/AP. Signal should overlap at around the 80% of degradation mark.

What are the differences between a router and an access point?

What is the Beacon Interval On A Wi-Fi Router?

You can download our free guide on setting up a wireless network if you want to learn more one setting up a second router/AP and more…

We hope this has helped you. Let us know all about it in the comments section below.

2 Comments - Write a Comment

  1. An article on changing txpower adjustment that it doesnt even give you a link on how to do it, let alone tell you how to do it – poor

    Reply
    1. · Edit

      Hi Anon,

      Sorry that you’re having issues adjusting the power. The article is not a How-To. We might add one in the future, this article is purely to explain why you would want to change the power, and the potential dangers of doing so.

      You should be able to find a ‘How to’ for your router (if it supports it) with a quick Google search… “Tx Power adjustment dd-wrt” for example. But if you are using DD-WRT, this video shows you where to look, assuming you are using the GUI: https://youtu.be/GgImHUTQ-6M?t=1m23s

      If you are using CLI, then try the following: https://www.dd-wrt.com/wiki/index.php/Advanced_wireless_settings#TX_Power

      Remember to only very finely tweak. And don’t add too much power, otherwise you risk frying your router.

      Good luck!

      Reply

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